The invention is primarily related to the handling of foodstuff pieces, e.g. for making portions of fish or chicken pieces. It is known that portions of such pieces can be built up by currently weighing the successively supplied pieces on a dynamic weight and thereafter, dependent of the weighing results, effect a selective supply of the pieces to different receiver containers placed along a further extending conveyor. What can be aimed at is that in the single containers total portions can be built up so as to have a desired weight, but it is required that the pieces are supplied one by one, such that an associated computer may all the time keep track of where the pieces are located.
With another known method for the making up of object portions the principle of combination weighing is used, whereby an unordered flow of objects is distributed so as to be received as undetermined portions in a number of weighing containers, in which the portions are weight determined, whereafter the computer looks for portions giving a total of the desired ultimate portion weight. Thereafter just these selected subportions are released into an underlying collector unit, typically a large hopper, from which they are delivered as one portion. For ensuring a good capacity it is actual here to make use of a considerable number of weighing units, and besides, these weighing systems, having the weighing units arranged in a straight or circular row, normally exhibit a considerable building height, because normally they comprise slanting sliding chutes for the objects/subportions. This also implies that these systems may well be suited for dry and rigid products, e.g. pastils and root crops, but not for soft and adhering products. For the invention it is a basic consideration that it will be possible to use the first mentioned working principle, i.e. using only a single dynamic weight, without the feeding flow of objects being ordered in consisting of single objects conveyed mutually spaced, namely if care is taken that an unordered feeding flow is caused, in a compulsory manner, to be separated in mutually spaced subportions, whether these comprising a single or more objects, prior to being fed to the dynamic weight. Hereby it is made possible to operate with the dynamic weighing even when the feeding flow is unordered, and also to operate with weighing portions comprising more objects; conventionally, the discussed weighing and sorting out principle has been associated with the handling of single objects, but it is highly advantageous when also plural object portions can be handled.
From EP-A-0,534,889 a combination weight using but a single weighing unit is known; an annular row of receiving containers, which would conventionally be stationary and each associated with a weighing unit, is arranged to be circularly movable such that the containers are successively passed over a weighing unit which, with deduction of tare, measures the weight of the single portions in the containers; these subportions may then be discharged in suitable combinations for collection in an underlying hopper, for which it is immaterial whether the circular container row rotates or stands still.
In this known portioning apparatus the supply of the unordered flow of objects takes place on a conveyor down to a fixed dropping area above the rotating ring of receiver containers. Thus, already by their passage of this area, the containers themselves will constitute the means required for separating the flow to the different containers, and vis-a-vis the invention the containers may thus be considered as means for achieving an ordering of the supply flow in mutually separated portions, which may then be weighed. It is here important, however, that while such a technique may be well suited for the handling of dry objects such as onions or other examples stated in said EP-A-0,534,889, it is absolutely unsuitable for the handling of soft, sticky objects. When supplied in the manner described an object of this type may well be deposited across the joint between two neighbouring containers, without rolling or sliding down therefrom, and the result will be highly disordered weighings and spoiled possibilities of an orderly delivery of the objects from the containers.
It is to be stressed, therefore, that the portioning separation of the supply flow of objects according to the invention has to be effected and terminated prior to the objects or groups of objects being fed to such moved containers or at least in direct connection with the feeding thereto, inasfar as it is acknowledged by the invention that despite the deviating approach it may still be very advantageous to effect the weighing in of the objects or object groups by a weighing of receiver containers that are moved in a closed path.
This requirement of a pre-portioning of the object flow makes it difficult to arrange the separation in such a manner that the objects or object groups follow each other so closely that they can be delivered with required safety to receiving containers advanced without mutual spacing. Normally it will be actual to arrange for the separation by some sort of forward or rearward pushing of objects in the arriving main flow for effectively overcoming the said overlapping problem, so the containers should be somewhat interspaced during the filling thereof. Thereafter the containers may well be brought together so as to take up a minimum of operative space.
Thus, it is hardly possible to use the carrousel principle disclosed in EP-A-0,534,889, where the containers are closely juxtaposed all the way round. The principle, at least, will have to be modified such that the containers are successively accelerated through a free path in connection with the filling; however, in connection with the invention it will normally be desired to use so many and so large containers that space requirements will make it non-desirable to use a circular system. It is already known from various systems with round-moving containers or conveyor trays to arrange these in such a manner that they are advanced by a chain in two straight, parallel runs between opposed sprocket wheels, and this is as tailored for the invention, because the containers may then be moved with close juxtaposition along the straight runs, while at the sprocket wheels they will radiate from these, i.e. they will exhibit increased mutual spacing, even when still being close to each other at their inner ends. By the associated swinging away from each other the containers will be loadable by marked separated object groups, such loading being possible in different ways.